26 January 2016

In my tooling around the Internet for Marmorkrebs related research, I found this risk assessment for Marmorkrebs as a potential non-indigenous crayfish in Ireland. It seems to be an extremely thorough document.

25 January 2016

A week ago, I reported stumbling upon information indicating that Marmorkrebs had been designated “Class V Wildlife” (basically, zoos only) in Tennessee. I can now confirm that this is correct. This effectively means that keeping Marmorkrebs as pets is now illegal in Tennessee.

Trying to track this down required a little effort. As I mentioned before, my initial Google searches failed miserably. Twitter to the rescue!

The Tennessee Wildlife Resources Agency has a Twitter account. They replied to my tweet, and gave me a phone number to try. It took several tries over multiple days to get a person instead of a voice message. When I did get through, I got another phone number to try, but luckily, got an answer to on the first call. And the person I spoke to was able to confirm that Marmorkrebs was added to Tennessee’s list of Class V wildlife last October.

People have kept Marmorkrebs in Tennessee: I found some owners discussing their pets in a previous paper (Faulkes 2013; data here). But I wonder how someone who wants to be a responsible, law-abiding pet owner is supposed to learn about this new regulation. I specifically watch for news about Marmorkrebs like a hawk, and I missed this item for three months. Then it took me almost a week of phone tag to track down someone who could confirm it. The Tennessee officials I spoke to on the phone were super helpful, but still, I put in considerable effort to learn this information. Not everyone will have my obsessive motivation.

There is a close association between parthenogenesis and polyploidy. For this reason, we undertook a karyological analysis to test whether the parthenogenetic Marmorkrebs, Procambarus fallax forma virginalis, possesses an enlarged set of chromosomes. For this purpose, we karyotyped the Marmorkrebs, the sexual form of P. fallax (together called P. fallax complex), and the closely related species P. alleni. The latter shows 94 chromosomes in the haploid condition. In contrast to this, we found a haploid set of 92 chromosomes in individuals of the P. fallax complex. However, in mitotic metaphases the sexual form shows 184 chromosomes, whereas the Marmorkrebs possesses 276 chromosomes. Hence, the parthenogenetic Marmorkrebs reveals a triple amount of the haploid chromosome number. In addition, we detected a strikingly large subtelocentric chromosome which appears once in haploid and twice in diploid cells of sexual individuals of the P. fallax complex. In the parthenogenetic Marmorkrebs, this prominent chromosome occurs thrice. All this clearly reveals that the Marmorkrebs is a triploid organism. The applicability of the used methods, the significance of polyploidy in evolution of Decapoda, putative pathways to parthenogenetic triploidy, a possible hybrid origin and the scientific and ecological consequences of an increased chromosome set in Marmorkrebs are discussed.

19 January 2016

I ran across a notice that Marmorkrebs have been added to Tennessee’s list of “Class V wildlife.” (Update, 25 January 2016: the link is already busted.) This is the entirety of the text I have right now (my emphasis and sics)

It would not surprise me if Marmorkrebs were the subject of legislation in Tennessee, because that state is near, if not the center, of the world’s hotspot for crayfish biodiversity. Non-indigenous crayfish could cause a large number of problems for indigenous crayfish species in Tenessee.

I wanted to confirm this, but, somewhat to my surprise, my initial tooling around in Tennessee government websites yielded nothing. Even with what appears to be a fairly detailed description of the source of information, I can’t find it.

Class V
--
This class includes such species that the commission, in conjunction with the commissioner of agriculture, may designate by rules and regulations as injurious to the environment. Species so designated may only be held in zoos under such conditions as to prevent the release or escape of such wildlife into the environment.

But I still can’t find a simple list of “Class V species” to figure out if Marmorkrebs are on it.

06 January 2016

The XXI Symposium of the International Association of Astacology will be held at the Royal Botanical Garden of the Spanish Research Council, CSIC, in Madrid, Spain, 5-8 September 2016. The symposium will include invited lectures, contributed oral and poster presentations, and exhibitions. The symposium will be followed by a 4-day post-symposium-excursion to visit crayfish populations, and production sites in Seville, Granada, and Donaña National Park. Registration will be open soon. For more information, contact Javier Diéguez-Uribeondo: dieguez@rjb.csic.es.

Photo by Nathan Rupert on Flickr; used under a Creative Commons license.